The invention discloses a multi-channel
signal amplifying circuit of a low-duty ratio narrow pulse
signal and a control method. The multi-channel
signal amplifying circuit of the low-duty ratio narrow pulse signal comprises a variable
gain amplifying circuit, an
adder circuit, a sampling keeping circuit and a master
control unit module, wherein the master
control unit module comprises a micro-control module; and an analogue-
digital conversion module, a trigger circuit and a digital-analogue conversion module are integrated inside the micro-control module. According to the control method of the multi-channel signal amplifying circuit based on the low-duty ratio narrow pulse signal, the
adder circuit can merge a plurality of paths of output signal amplitudes of the variable
gain amplifying circuit into a path of signal; the micro-control module in the master
control unit module judges the signal amplitude output by the
adder circuit, and adjusts the
voltage change output by the digital-analogue conversion module, so that the
gain of a
voltage-programmed
variable gain amplifier is correspondingly changed, and the adder circuit outputs the pulse signal amplitude to stabilize at a set numerical value, so that a
dynamic range output by the
variable gain amplifier is reduced.